Austen Ivereigh, Director of Public Affairs for the Diocese of Westminster, has resigned following media reports that a former girlfriend had an abortion 20 years ago before he had returned to the Church.

The Times reports that Dr Ivereigh, who is single, has never denied that a girlfriend had an abortion while he was a student at Oxford.

He was not a practising Catholic at the time, and the episode is understood to have prompted his return to the faith.

After a relationship with a more recent girlfriend ended, the media has reported that she had been pregnant, but had miscarried twins.

Dr Ivereigh, 40, who has often spoken in support of the Church's stance against abortion, is taking legal action over some of the reporting.

He was educated at Worth Abbey, a public school in West Sussex, run by Benedictine monks. He rebelled as a teenager but, after rediscovering his faith, became such a committed Catholic that he considered becoming a monk. He worked a journalist and deputy editor at the Catholic publication The Tablet, before joining the Cardinal's staff.

He said yesterday: "When I represent the Church's teaching on abortion there is no hypocrisy on my part. I do so not just with sincerity but from experience. To say that abortion is the taking of human life is not to condemn anyone who has had one."

He continued: "We who speak on behalf of the Church, on behalf of Christ, we are not qualified to do so, we are not worthy to do so. We do so because faith is a gift."

Dr Ivereigh declined to comment on any of his relationships but insisted that he was not guilty of any hypocrisy on abortion. He said that he was resigning "as a result of persistent and untrue reports about my private life".

He continued: "The decision, which has been my own, was taken in order to avoid further distractions from the Cardinal's crucial role as Archbishop of Westminster."

He said that he was grateful for the "compassionate and wise guidance" he had received from the Cardinal. Dr Ivereigh added: "Throughout my time at Archbishop's House, and especially in recent weeks, I have been humbled by the witness to the Gospel given to me by so many Catholics. I will continue to serve the Church in any way I can."

The Cardinal said last night: "I want to put on record my sincere thanks to Austen for all he has done on my behalf and for the Church in the past year and a half. I wish him well in the future."